Project Summary Obesity is characterized by a shift in energy balance, and changes in energy balance can be important contributing factors in the etiology of diabetes and other metabolic diseases. Measurement of the factors that influence energy balance is fundamental to understanding the mechanisms influencing obesity and weight change with metabolic disorders or disease. The techniques that are used to measure the factors that influence energy balance often involve moving animals to an environment that is different from the home cage, and stress induced during these measurements may influence energy balance and confound the measurements. We propose to complement existing UC Davis campus research strengths in diabetes and obesity, exercise physiology and muscle biology, and nutrition and energetics through the purchase of a pipeline of equipment for assessing factors that influence energy balance in a home cage environment. This equipment would respond to investigator requests for research services that will minimize stress while assessing factors that contribute to alterations in body weight and composition in their mouse models. The proposed equipment has the capability to accurately measure food intake (BioDAQ home cage automated episodic food & liquid Intake monitor), energy expenditure (home cage Comprehensive Lab Animal Monitoring System, HC-CLAMS), body composition (EchoMRI-2n1-100TM Vertical Whole-Body Composition Analyzer) and diet energy digestibility (Parr 6200 Isoperibol Calorimeter). This equipment also has the advantage of being able to accommodate large numbers of mice, thus enabling individual investigators to complete statistically-robust studies in relatively short periods of time and allowing for broader-based metabolic phenotyping efforts in mouse models through the UC Davis Mouse Metabolic Phenotyping Center and the Mouse Biology Program. Seven NIH funded faculty with 15 active grants (14 NIH & 1 USDA) are named major and minor users of this equipment.